But the writers of the show are working hard to keep everything under wraps. “We literally consulted with the producers on Game Of Thrones to learn security protocols,” said executive producer Shawn Levy.

“We had no security protocols last season and we have extensive security protocols this season. I can’t speak about what they are because then people could crack them. We protect every story point, every page of every script.”

The team are now literally burning away any lingering evidence of what could be coming, with co-creator Ross Duffer admitting to Entertainment Weekly: “I used to throw my sides away and now they have to be burnt.”

Millie Bobby Brown, who plays Eleven, also revealed the length the cast have gone to keep the plot a secret.

“Now we have a code name (for the show). And now I have a code name!” she said.

“It’s this weird thing. On the call sheets our names are across it and if we lose it, we’re dead.”

Despite that, a few details have recently emerged about the plot in Season Two with co-creator Matt Duffer explaining that the character of Will Byers – who went missing in Season One – now “seems to be seeing images from the Upside Down – the question is whether they’re real or not. So it seems like he’s having some sort of post-traumatic stress disorder.”

Byers’ mother, Joyce (Winona Ryder), is now dating an old high school classmate, Bob (played by The Goonies’ Sean Astin) and is “trying to mask a lot,” according to Ryder. “I think she’s made this choice with Bob because she wants a good father figure in her sons’ lives.”